# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
from scrapy.http.request import Request


class DuokanSpiderMiddleware(object):
  # Not all methods need to be defined. If a method is not defined,
  # scrapy acts as if the spider middleware does not modify the
  # passed objects.

  @classmethod
  def from_crawler(cls, crawler):
    # This method is used by Scrapy to create your spiders.
    s = cls()
    crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
    return s

  def process_spider_input(self, response, spider):
    # Called for each response that goes through the spider
    # middleware and into the spider.

    # Should return None or raise an exception.
    return None

  def process_spider_output(self, response, result, spider):
    # Called with the results returned from the Spider, after
    # it has processed the response.

    # Must return an iterable of Request, dict or Item objects.
    for i in result:
      yield i

  def process_spider_exception(self, response, exception, spider):
    # Called when a spider or process_spider_input() method
    # (from other spider middleware) raises an exception.

    # Should return either None or an iterable of Response, dict
    # or Item objects.
    pass

  def process_start_requests(self, start_requests, spider):
    # Called with the start requests of the spider, and works
    # similarly to the process_spider_output() method, except
    # that it doesn’t have a response associated.

    # Must return only requests (not items).
    for r in start_requests:
      yield r

  def spider_opened(self, spider):
    spider.logger.info('Spider opened: %s' % spider.name)


class DuokanDownloaderMiddleware(object):
  # Not all methods need to be defined. If a method is not defined,
  # scrapy acts as if the downloader middleware does not modify the
  # passed objects.

  @classmethod
  def from_crawler(cls, crawler):
    # This method is used by Scrapy to create your spiders.
    s = cls()
    crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
    return s

  def process_request(self, request, spider):
    # Called for each request that goes through the downloader
    # middleware.

    # Must either:
    # - return None: continue processing this request
    # - or return a Response object
    # - or return a Request object
    # - or raise IgnoreRequest: process_exception() methods of
    #   installed downloader middleware will be called
    url = request.url
    book_id = url.split('/book/')[-1]
    #book_id = url.split('?x=')[-1]

    if book_id.isdigit():
      book_id = long(book_id)
      if book_id %10 == 1:
        for x in xrange(1, 10):
          spider.crawler.engine.crawl(Request(url=url.rstrip(str(book_id)) + str(book_id + x)), spider)

    return None

  def process_response(self, request, response, spider):
    # Called with the response returned from the downloader.

    # Must either;
    # - return a Response object
    # - return a Request object
    # - or raise IgnoreRequest
    return response

  def process_exception(self, request, exception, spider):
    # Called when a download handler or a process_request()
    # (from other downloader middleware) raises an exception.

    # Must either:
    # - return None: continue processing this exception
    # - return a Response object: stops process_exception() chain
    # - return a Request object: stops process_exception() chain
    pass

  def spider_opened(self, spider):
    spider.logger.info('Spider opened: %s' % spider.name)
